To capture particulate matter (PM) in an exhaust gas from an internal-combustion engine such as a diesel engine, a dedicated filter (i.e., DPF: Diesel Particulate Filter) is typically used. In order to comply with exhaust gas regulations, an exhaust aftertreatment device with a DPF is equipped in, for instance, an on-road transport truck using a diesel engine. The exhaust aftertreatment device is usually uncovered and located in an exhaust pipe extending from the engine at a position where the device is likely to be exposed to wind during the traveling of the vehicle (e.g., the lower side of the vehicle).
When an exhaust aftertreatment device is located on the lower side of a tired construction vehicle, the exhaust aftertreatment device may be hit by gravel stones thrown up during the traveling of the vehicle or be sunk into mud along with the vehicle, resulting in damage to the exhaust aftertreatment device. In view of the above, it has been suggested that when an exhaust aftertreatment device is equipped in a dump truck, the exhaust aftertreatment device be located alongside a cab, in which an operator rides, and at such a high position as the top of a fender for the right front wheel (see, for instance, Patent Literature 1, FIG. 1).
Recently, stricter regulations on exhaust gas emission require further purification of an exhaust gas. Accordingly, it is preferred that an exhaust aftertreatment device be equipped with a reduction catalyst used to purify a nitrogen oxide in an exhaust gas in addition to the DPF. The reduction catalyst is used in, for instance, SCR (Selective Catalytic Reduction). For SCR, a reductant such as a urea aqueous solution is necessarily supplied into the exhaust gas. Accordingly, the construction vehicle is equipped with a reductant tank for storing the reductant, a supply pump for supplying the reductant, and an injector adapted to inject the reductant.
Patent Literatures 2 and 3 each disclose an SCR-equipped exhaust aftertreatment device for an automobile or a bulldozer (not for a tired construction vehicle) and installation of a reductant tank and a supply pump.
Specifically, Patent Literature 2 discloses that a fuel tank and a reductant tank are unified. Patent Literature 3 discloses that a reductant supply pump is located in a dent formed on an outer surface of a reductant tank.
Additionally, according to some references (specific titles thereof are omitted), it is known that an upper rotary body of a crawler hydraulic excavator may be equipped with a reductant tank, the reductant tank being located in a housing space, which is covered with an exterior cover, being opposite to a cab (in which an operator rides) across a boom (i.e., a working equipment).